Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 5th Sem New 2152301 Injection Molding Technologies Previous Question Paper
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (NEW) EXAMINATION ? WINTER 2018
Subject Code:2152301 Date:27/11/2018
Subject Name:Injection Molding Technologies
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) (1) The L/D ratio for a general purpose screw is ________.
(2) What is the function of a nozzle?
(3) Define melt flow index.
03
(b) (1) List any two molding defects of injection molding.
(2) What is maximum day light of a mold?
(3) List the main types of clamping systems for injection
molding.
(4) The clamping pressure should be more than the
injection pressure (True & False)
04
(c) Define Injection Molding. List advantages and
disadvantages of it.
07
Q.2 (a) Calculate the clamping force a press with a hydraulic
clamp has a 600 mm diameter clamping cylinder and
hydraulic line pressure is 2000kg/cm
2
.
03
(b) Explain predrying of thermoplastic materials. 04
(c) Explain basic principles of Reciprocating screw machines
in detail with neat sketch.
07
OR
(c) List various directional control valves used in Injection
Molding machine. Explain any one with neat sketch.
07
Q.3 (a) What is nitriding? Explain importance of screw nitriding. 03
(b) Explain the start up and shut down procedure for injection
molding process.
04
(c) Compare: Injection Molding of Thermoplastic with
Injection Molding of Thermosets.
07
OR
Q.3 (a) What are the major causes of breakdown of plunger
cylinders?
03
(b) Explain the injection cycle. 04
(c) Define: (1) Injection shot capacity (2) plasticizing
capacity (3) back pressure (4) maximum day light (5)
compression ratio (6) injection pressure (7) minimum day
light.
07
Q.4 (a) List the advantages and disadvantages of toggle clamping. 03
(b) Explain the needle type shut-off nozzle
04
(c) List various functions carried out by the microprocessor
of Injection molding machine. Also Explain about close
loop and open loop control system.
07
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
FirstRanker.com - FirstRanker's Choice
www.FirstRanker.com
1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?V (NEW) EXAMINATION ? WINTER 2018
Subject Code:2152301 Date:27/11/2018
Subject Name:Injection Molding Technologies
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) (1) The L/D ratio for a general purpose screw is ________.
(2) What is the function of a nozzle?
(3) Define melt flow index.
03
(b) (1) List any two molding defects of injection molding.
(2) What is maximum day light of a mold?
(3) List the main types of clamping systems for injection
molding.
(4) The clamping pressure should be more than the
injection pressure (True & False)
04
(c) Define Injection Molding. List advantages and
disadvantages of it.
07
Q.2 (a) Calculate the clamping force a press with a hydraulic
clamp has a 600 mm diameter clamping cylinder and
hydraulic line pressure is 2000kg/cm
2
.
03
(b) Explain predrying of thermoplastic materials. 04
(c) Explain basic principles of Reciprocating screw machines
in detail with neat sketch.
07
OR
(c) List various directional control valves used in Injection
Molding machine. Explain any one with neat sketch.
07
Q.3 (a) What is nitriding? Explain importance of screw nitriding. 03
(b) Explain the start up and shut down procedure for injection
molding process.
04
(c) Compare: Injection Molding of Thermoplastic with
Injection Molding of Thermosets.
07
OR
Q.3 (a) What are the major causes of breakdown of plunger
cylinders?
03
(b) Explain the injection cycle. 04
(c) Define: (1) Injection shot capacity (2) plasticizing
capacity (3) back pressure (4) maximum day light (5)
compression ratio (6) injection pressure (7) minimum day
light.
07
Q.4 (a) List the advantages and disadvantages of toggle clamping. 03
(b) Explain the needle type shut-off nozzle
04
(c) List various functions carried out by the microprocessor
of Injection molding machine. Also Explain about close
loop and open loop control system.
07
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
www.FirstRanker.com
2
OR
Q.4 (a) State the functions of three zones of the injection screw. 03
(b) Compare hydraulic drive with electric drive. 04
(c) Explain about Gas Assist Injection molding process. 07
Q.5 (a) Explain about material selection criteria for injection
molding process.
03
(b) Compare hydraulic clamping with toggle clamping
(Any four points)
04
(c) Explain about pressure profile in cavity with suitable
graph.
07
OR
Q.5 (a) Give causes and remedies of the following defects:
(1) Short-shots (2) warpage (3) weld line
03
(b) For PVC which type of screw tip is used? Why? Explain
it with neat sketch.
04
(c) Explain RIM process in detail. 07
*************
www.FirstRanker.com www.FirstRanker.com
www.FirstRanker.com
FirstRanker.com - FirstRanker's Choice
This post was last modified on 20 February 2020